Piston-packing.



No. 856,992. PATENTED JUNE 11 1907. R. R. SPEARS. PISTON PACKING.

APPLIOATION FILED NOV. 30. 1906.

1 8 I Ralphfi'SpeWS/ 5W UNITED STATES PATENT OFFICE.

PISTON-PACKING.

Specification of Letters Patent.

Patented June 11, 1907.

Original application filed June 14, 1906, Serial No. 321,674. Dividedand this applieationfiled November 30, 1906. Serial No. 345,714.

To all whom it may concern:

Be it known that I, RALPH R. Srniins, a citizen of the United States,residing at I/Vheeling, in the county of Ohio and State of est Virginia,have invented a new and useful Piston-Packing, of which the following isa specification.

This invention relates more particularly to packing for pistons in thattype of motors wherein the motive fluid is alternately supplied to andexhausted from the cylinder on opposite sides of the piston, though thesaid invention is, perhaps, useful in other relations. 7

The present application is a division of eopending application, SerialNo. 321,674.

The principal object is to provide a piston packing wherein the dangerof leakage past the piston is reduced to a minimum and the wear of theparts is automatically compensated for.

The preferred form of construction is illustrated in the accompanyingdrawings, wherein Figure 1 is a sectional view through a motor with thepiston shown in elevation and provided. with the novel packing; Fig. 2is a sectional View on the line 2-2 of Fig. 1; Fig. 3 is a detail planview of the annular packing band; Fig. 41 is an end view of the same.

Similar reference numerals designate corresponding parts in all thefigures of the drawings.

In order that the applicationof the novel structure may be clearlyunderstood, the same is shown in place in a motor which constitutes thesubjeet-matter of the aforementioned copending application.

Briefly described, this motor consists of a cylinder 5, in whichoperates a reeiprocatory piston 6, provided with a piston rod in theform of tubes or pipes 7 and 8 that extend through opposite heads of thecylinder and constitute, respectively, supply and exhaust pipes. Thesepipes are in communication with the cylinder on opposite sides of thepiston through ports 9 and 10 controlled, re speetively, by valvemechanisms 11 and 12, as fully set forth in the said co-pendingapplication. Inasmuch as the pressure is alternately upon opposite sidesof the piston, it is necessary to provide against leakage past thepiston in both directions. The following novel means has proven highlyeffective for the purpose.

The piston 9 is of less diameter than the cylinder and is provided inits periphery with an annular groove 13. A band 14 of leather or otherflexible material surrounds the piston and has an intermediate in-setportion 15 seated in the groove 13. Retaining wire 16 is-wrapped into aplurality of convolutions around the inset portion 15, the wire beingheld against unwrapping by soldering the convolutions together atsuitable intervals, as shown at 17 in Fig. 1. The marginal portions 18of the band are free and constitute, in effect, extensible flaps thatwill freely spread, and thus at all times co-operate with thecylindrical wall of the cylinder. The abutting ends of the band are outdiagonally, as shown in Figs. 1 and 3.

Experience has demonstrated that in mechanism of this type, the nearerthe wellknown cup packing can be approached, the less liability there isof leakage, but inas much as the valve mechanisms 11 and 12 pro j ectthrough the opposite sides of the piston, cup paekings cannot beemployed. The

structure disclosed, however, has practically all the advantages of cuppaekings for the oppositely extending margins of the band or ring arefree so that the motive fluid can enter between them and the pistonbody, thus forcing them outwardly and insuring a tight joint during theopposite movements of the piston and without regard to the wear of theparts.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In mechanism of the character set forth, the combination with acylinder, of a reciproeatory piston operating therein and having anannular groove in its periphery, a band of flexible material surroundingthe periphery of the piston, said band having its intermediate portionlocated in the groove and of less thickness than the depth of saidgroove, and its side margins free and disposed on opposite sidesthereof, and means extending around the outside of the said intermediateportion of the band and located in the groove of the piston to maintainsaid portion therein.

2. In mechanism of the character set forth, the combination with acylinder, of a reciprocatory piston operating therein, and having anannular groove in its periphery a band of and having its severalconvolutions soldered 1o flexible material surrounding the piston, saidtogether. band having an intermediate inset portion In testimony, that Iclaim the foregoing as located in the groove of the piston and havmyown, I have hereto aflixed my signature lng its side margins free andprojecting bein the presence of tWo Witnesses.

yond the opposite sides of said inset portion, RALPH R. SPEARS. and aWire Wound into a series of convolu- Witnesses: 7 tlons around the saidinset portions of the LAVINIA M. CARROLL,

band, said Wire being located in the groove 4 MAUDE E. MURRIN.

